The former chief of Venezuela's military intelligence - and the highest-ranking military officer to defect to the US-backed opposition - has been nabbed in Spain on a US warrant for allegedly trafficking tons of cocaine.

Hugo Carvajal was arrested by Spanish police in Madrid on Friday and faces extradition to the US, where he was indicted in 2014 for allegedly having "coordinated the transportation of approximately 5,600 kilograms of cocaine from Venezuela to Mexico." He will testify in a Saturday court appearance as to whether he wishes to fight the extradition, an official with Spain's National Court told the AP.

The Venezuelan ex-major general, whose nickname "el Pollo" means "the Chicken," is accused of protecting a Colombian drug kingpin from arrest, allowing him to move about 5,600kg of cocaine in and out of Venezuela, and tipping him off to law enforcement activities. Carvajal allegedly was not only paid off by the kingpin and other members of his organization, but also invested in some of the drug shipments. He is also accused of providing weapons to the Revolutionary Armed Forces of Colombia (FARC).

While Carvajal served as chief of military intelligence and counterintelligence under former Venezuelan president Hugo Chavez, he reportedly began to distance himself from Chavez's successor President Nicolas Maduro after returning to Venezuela in 2014 from Aruba, where he had been briefly detained on the same US warrant, facing extradition until Maduro threatened retaliation against the island.

Carvajal left Maduro's government in 2017, ostensibly in protest over the president's plans to form a constitutional assembly that would reduce the power of the opposition-controlled National Assembly, and declared his allegiance to opposition leader and self-appointed president Juan Guaido in February, blaming Maduro for the "disastrous reality" of Venezuela. Last month, the president expelled Carvajal from the armed forces, accusing him of "acts of treason against the fatherland."

Since embracing the US-backed Guaido, Carvajal has called on other members of the Venezuelan military to join the opposition, warning them against becoming "collaborators" of a "dictatorial government that has plagued people with misery" and accusing military leaders of being pawns of Cuba. He also gave a juicy interview with the New York Times, denouncing current and former members of Maduro's government as drug traffickers, FARC and Hezbollah collaborators, and journalist blackmailers while denying his own guilt on the many of the same charges.